Patent GB-380788-A (GB)
Title: Apparatus for the remote control and supervision of adjustable members in a sub-station from a main station
IPC: H02J13/00
Filed: 1931-06-12
Abstract: 380,788. Electric signalling and remote control systems. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. June 12, 1931, No. 17136. Convention date, June 13, 1930. [Class 40 (i).] In an electric signalling and/or remote control system, signalling pulses are transmitted over synchronously moved distributers at the two stations which are each arranged to move one step on receipt of a pulse from the other station and then to make a further step over a local circuit, the stepping pulse being sent to the remote station during the second of such steps and being used, when necessary, for signalling or control purposes, distinction between stepping pulses and combined stepping and actuating pulses being obtained by current reversal. To prevent incorrect operation of remote apparatus, control may be made dependent on the receipt of two pulses at different points in the transmission cycle, the former of which operates a relay which prepares the circuit of the associated control relay. Where several controlled elements are provided, the preparation and control relays may be grouped on to consecutive odd contacts of the substation distributer, the leads to the preparation and control relays being arranged in reverse order. A preparation relay may prepare circuits for more than one control relay. Signalling of automatic switch changes and of meter readings is provided. The distributers may be replaced by relay chains. Stepping circuits. The circuits for driving the distributers are shown in Fig. 1, the distributer on the left being at the main station and that on the right at the substation. Two wires are provided one of which Ltg2 joins the wipers I and the other Ltg1, which can be replaced by earth, connects the mid-points of the batteries (not shown) at the two stations. When the start key AT is depressed relay A energizes and slow relay VA pulls up. When the key is released A falls away and Da energizes, stepping the main station switch onto its contacts 1. The normal position of the substation switch is on contact 1 and consequently, when the main station distributer moves to contact 1, a circuit is completed over Ltg2 to energize C. Slow relay Vb pulls up. When Va de-energizes F operates, completing a circuit for Da and the main station switch moves to position 2, where F falls away. In position 2 the circuit over Ltg2 is broken enabling C to release and Db energizes stepping the substation distributer to position 2. With both switches in position 2, A is energized over Ltg2 which completes a circuit for Va as before described. When Vb de-energizes, G pulls up and completes a circuit for Db which moves the substation selector on to its third contact. The circuit for A is thus broken and the main station distributer moves into its third position and the cycle is repeated. Stepping on rebound is prevented, after steps controlled by relay A (or C), by connecting Da (or Db) to positive on wiper II, and for locally controlled movements, by making a locking circuit for the magnets over f2 (or g2), which is closed before and opened after the energizing circuit over f3 (or g3). Operation of A or C by line discharges is prevented by f1 and gl. Remote signalling. Figs. 2 and 3 indicate the application of the invention to a remote signalling and control system. Two additional banks III and IV are provided at the main station, Fig. 2, and one additional bank III is necessary at the substation, Fig. 3. To check the position of the remote indicators start key AT is depressed which energizes VC ; and A pulls up, allowing the distributer to traverse a complete cycle. The second and fourth contacts of bank I of the substation distributer are connected to contacts osa1, osb1 respectively, which are controlled directly by circuitbreakers. When this switch reaches its second contact, as osa1 is making its left-hand contact, a negative pulse is transmitted to the main station. Polarized relay Pa responds, completing parallel circuits for A, which prepares the stepping circuit, and for polarized relay Rc, which moves its armature to complete a circuit for L3 or L4 to indicate the position of OSA (not shown). Similarly in the fourth position relay Rd is operated to control L5 or L6 to indicate the position of OSB. Remote control. To transmit a control, a key such as StT1 (which may be either a hand controlled switch or a relay contact) is operated and the apparatus is set in motion. When wipers I reach their seventh contacts, the pulse over Ltg2 is reversed and Pb completes parallel circuits for B and C. C completes the stepping circuit as before described, and B allows StV to energize over II and complete the required operations. A remote operation may be made to depend on the operation of two separately controlled relays such as StV and St. Two contacts StT1 and StT2 are operated under these conditions, the first causing a negative pulse to be sent in the seventh position, which energizes StV, and the second causing a negative pulse to be transmitted in the thirteenth position. StV locks to contacts rst, which are opened by Rst when the switch is normal, and prepares the circuit to allow St to be energized on the second control pulse. Relay St locks to Abst, which is opened when the remote operation is completed, and energizes an alarm L. Where several remote elements are to be operated the preparation relays, such as StV, and the control relays, such as St, are grouped together and are connected to contacts of bank II in reverse order, thus eliminating the risk of incorrect control. Control preparation relays may be common to several control relays, for example one preparation relay may be used for the two relays which move a circuit breaker into its " in " and " out " positions respectively. Remote testing or metering. If the key T1 is depressed and the apparatus is started, relay H energizes in the second position and locks, breaking the circuit to F and placing negative on the odd contacts of bank I. The switches move to the third position and, as F fails to operate, the main station switch stops and L1 lights. A negative pulse is received at the substation, B is energized, but as the second winding of C is not connected to the third contact, this relay does not respond. Ra operates and Mh pulls up. Meter MZ is connected across E1 and impulses are transmitted to the main station, the frequency of which indicates the value measured. The rectifier GL2 prevents these pulses from affecting Pb. When the testing is to be ended, the starting key AT is depressed, Vc energizes and releases H, F pulls up to step the main station switch and a pulse is transmitted over Ltg2 which operates Pb, over GL2, and allows the two switches to restore. The depression of T2 allows the value E2 to be measured. Signalling of automatic movement of adjustable members. The apparatus, when not otherwise employed, is set in one of its meter-reading positions. When an adjustable member changes its position, the holding circuit of Alb is broken at contacts such as osa2. The release of Alb opens the circuit over Ltg2 and supervising apparatus J, of known type, operates an alarm Al. The operator then sets the distributers in operation and the apparatus positions are signalled back as before described. The second alarm relay Ala enables an alarm to be given if a member should change over whilst the wipers are revolving. A red lamp RI, is illuminated when remote testing is not in progress and a lamp NL when the switches are normal. The red lamp may be replaced by an alarm. A system in which the operation of an adjustable member sets the switches in operation automatically is described in the Specification. Re-establishment of synchronism. Should the distributers fall out of step, the wipers at the main station stop on an even contact. The key Sytb is depressed and the distributers move until the substation distributer reaches its normal position. Relays Sya, Syb and N release to prevent commands or signals being transmitted during this " out of step " movement. When the substation switch reaches its normal position, the key Syta is operated to open the line Ltg2 and then Sytb is operated a sufficient number of times to step the main station distributer to its normal position. The distributers are then allowed to make two revolutions, Sya energizing in the 15th position of the first cycle to reclose the signalling and control circuits and Syb on the 14th stop in the second cycle to reclose the testing circuits. Alternative arrangements. Another embodiment of the invention is described in which the distributers make a cycle automatically if the battery potential at either station should fail or if the line circuits should be interrupted and are again closed, and in which relays are provided which stop impulse transmission and reset the switches to zero if the impulses are of incorrect duration. The preparation and control relays are grouped on different parts of the substation switch bank and an extra long impulse, delivered as the switch moves from one group to the next, checks that the switches are in synchronism at this point. The systems described above might continue to operate if the switches fall out of step by an even number of steps but this difficulty is overcome in a further embodiment of the invention described in the Specification. The use of the full battery potential for metering purposes, instead of half the potential as in the system outlined above, is also described.